Extensor Tendon Repair

Indications

  • Open laceration with loss of active extension at the affected joint.
  • Kleinert and Verdun zones I to VIII. Odd zones overlie the DIP, PIP, MCP and wrist.
  • Zone I injury causes mallet finger.
  • Zone III central slip division causes boutonniere deformity, with PIP flexion and DIP hyperextension.
  • Elson test detects acute central slip injury.
  • Zone V wound over the MCP after a punch is a fight bite and needs washout.
  • Sagittal band rupture at zone V causes extensor subluxation, usually ulnar.

Position

  • Supine with hand table and upper arm tourniquet.

Operative Steps

  1. Debride the wound and extend the incision, protecting dorsal veins and sensory nerves.
  2. Retrieve the proximal stump using wrist flexion and proximal massage.
  3. Zones I and II use a fine running or figure-of-eight suture, with DIP pinning if tenuous.
  4. Zone III repair secures the central slip to the middle phalanx base with suture or anchor.
  5. Zones IV to VII use braided nonabsorbable multistrand core suture, such as modified Kessler, then epitendinous suture.
  6. Zone IV tendon is flat, so horizontal mattress or running sutures suit it.
  7. Zone V repair includes the divided sagittal band, centralising the tendon over the metacarpal head.
  8. In zone VII, release part of the retinaculum and reconstruct a gliding tunnel afterward.
  9. Flex the finger passively to confirm the repair glides without gapping, then close.

Postoperative Care

  • Zone I splint holds the DIP in extension continuously for 6 to 8 weeks.
  • Zones III and IV splint the PIP in extension for 4 to 6 weeks, allowing DIP flexion.
  • Zones IV to VII allow early controlled motion with a relative motion extension splint or dynamic splint.

Complications

  • Extensor lag from tendon lengthening or repair gapping.
  • Loss of flexion from dorsal adhesions.
  • Repair rupture with early unprotected flexion.
  • Boutonniere deformity from missed or failed central slip repair.
  • Swan neck deformity from unrecognised or untreated mallet injury.
  • Septic arthritis of the MCP after fight bite.
  • Recurrent extensor subluxation after sagittal band repair failure.

Reviewed by Professor Phong Tran, Head of Orthopaedic Surgery, Western Health. Last updated 12 October 2026.